Former world No. 5 Sara Errani has been suspended for two months after failing a doping test, the International Tennis Federation has announced.

Errani, who reached the French Open final in 2012 and is now ranked No. 98, tested positive for letrozole, a substance commonly used in the treatment of breast cancer, during an out-of-competition test in February.

It has now been revealed that Errani, 30, of Italy, accepted a charge of violating anti-doping rules in April. The ban, effective from Aug. 3, was imposed after the case was heard by an independent tribunal last month.

The tribunal accepted Errani's claims that she had probably accidentally ingested drugs being used by her mother to treat breast cancer.

The written reasons for the verdict revealed Errani had been visiting her mother prior to the date of her positive test on Feb. 16. Her mother routinely stored her drugs close to an area used to prepare food and contamination was possible because there had been times when pills had been dropped or spilled.

The presence of the substance in Errani's system could not be completely overlooked but the tribunal accepted it was taken unintentionally.

Letrozole can help increase body mass and has been banned for all athletes since 2005 following concerns from the World Anti-Doping Agency it was being abused by bodybuilders. There is no evidence it would enhance the performance of an elite tennis player.

The violation could have resulted in a two-year ban but, after considering the evidence, a two-month suspension was deemed sufficient. Errani was tested again on June 7 and that proved negative.

All her results between the two tests have been annulled, meaning she must forfeit ranking points and prize money accrued between these days. She will be eligible to play again from Oct. 3.

Later Monday, the U.S. Open announced Errani had officially withdrawn. Denisa Allertova, of the Czech Republic, then moves into the main draw and American Samantha Crawford replaces Allertova in qualifying.

In a statement released on her official Twitter account, Errani strenuously denied knowingly taking a banned substance.

It read: "I never took, in my life and during my career, any prohibited substance. From the first day I have turned pro I always followed precisely the WADA program; I never asked for any therapeutic exemption to use any banned substances, not even when needed because [I was] ill.

"However, this substance is present in Femara, a medicine my mother has been using daily since 2012 for therapeutic purpose, further to a surgery for breast cancer, and therefore is present in the house where I am currently living.

"Together with my family, we have tried to understand how this contamination could have happened, because I am 100% certain I haven't taken a pill by mistake.

"The only viable option has been that an accidental food contamination occurred at some stage in the house. This option has been supported by a further hair test to which I voluntary underwent."

In a statement released via her official Twitter account, Errani strenuously denied knowingly taking a banned substance.

It read: "I never took, in my life and during my career, any prohibited substance. From the first day I have turned pro I always followed precisely the WADA program; I never asked for any therapeutic exemption to use any banned substances, not even when needed because [I was] ill.

"However, this substance is present in Femara, a medicine my mother has been using daily since 2012 for therapeutic purpose, further to a surgery for breast cancer, and therefore is present in the house where I am currently living.

"Together with my family, we have tried to understand how this contamination could have happened, because I am 100% certain I haven't taken a pill by mistake.

"The only viable option has been that an accidental food contamination occurred at some stage in the house. This option has been supported by a further hair test to which I voluntary underwent."